https://doi.org/10.1351/goldbook.12816
Temperature at which a thermoplastic polymer reaches a specific degree of softness as measured by a standard test.
Notes:
- Usually this temperature is determined using standardised methods, such as indentation tests, or the ring-ball method that characterise the dimensional stability of a polymer to heating. These standardised methods are often polymer specific.
- For an amorphous polymer, the softening temperature is close to the glass-transition temperature, and for a crystalline polymer the softening temperature is close to but lower than the melting temperature.